The present application pertains to rechargeable lithium ion batteries, and in particular, to a compact lithium ion battery module utilizing bipolar electrodes.
Lithium batteries are seen by many to be an attractive energy storage device. Lithium ion batteries have been targeted for various applications such as portable electronics, cellular phones, power tools, electric vehicles, and load-leveling/peak-shaving. The batteries are currently replacing many other traditional power sources such as lead acid batteries, nickel cadmium batteries, and nickel metal hydride batteries. Lithium ion batteries have been known to be out for many years (see the Handbook of Batteries, David Linden, editor, second edition by McGraw-Hill, copyright 1995, in particular, chapters 36 and 39). Various aspects of lithium batteries have been described in a variety of U.S. Patents, such as U.S. Pat. No. 5,961,672 pertaining to a stabilized anode for lithium polymer batteries. U.S. Pat. No. 5,952,126 pertains to polymer solid electrolyte and lithium secondary cells. U.S. Pat. No. 5,900,183 pertains to polymer electrolytes as well as does U.S. Pat. No. 5,874,185. U.S. Pat. No. 5,849,434 describes non-aqueous electrolyte lithium secondary batteries. Other variations on lithium batteries are described in U.S. Pat. Nos. 5,853,914 and 5,773,959.
Appropriately packaging lithium ion batteries is particularly difficult in the automotive environment due to the need for corrosion resistance, crush and crash worthiness, and vibration resistance. The problems of such batteries can be characterized as a need for better seal robustness, namely overcome leak potential from internal pressure; better packaging robustness, namely better crush/crash worthiness; better thermal exchange properties, namely ability to dissipate heat and receive cooling more effectively; ease of processing and transitioning into mass production, that is, processes that lend themselves to automation.
It is an object of the present invention to provide a lithium ion battery wherein bipolar electrodes are utilized with a lithium ion permeable polymer membrane or separator there between, and the cell electrodes being electrically connected appropriately to the anode and cathode terminals which are at opposite ends of the housing for the battery.
Described is a lithium ion battery 10 comprising:
A housing 12 having a front side 13 and a backside 15 and an anode terminal 60 and a cathode terminal 44 separated therefrom;
positioned within the housing a plurality of bipolar lithium ion cells 40 having a polymer separator 32 there between, optionally a lithium ion permeable membrane; the cell electrodes being comprised of a thin film plastic substrate 34 and being electrically connected appropriately to the anode and the cathode terminals, respectively;
wherein the cells are longitudinally placed in the housing parallel to the sides of the housing; and
wherein the housing is enclosed by the cathode terminal at one end and the anode terminal at the opposite end of the housing; and
the enclosed housing is capable of receiving an electrolyte placed between the cells and the electrolyte is capable of carrying ions between the anode and the cathode.